The present invention relates to extraction of scale, corrosion, deposits and contaminants from within conduits and on equipment utilized in the transmission of fluid columns, and further relates to the removal of contaminants that may accumulate within fluid columns transferred in such conduits.
It is common for contaminant deposits to accumulate within the inner walls of conduits and equipment utilized in the transportation and transmission of fluids from one location to another. In oilfield pipelines, for example, a mixture of oil, water and minerals may flow out of a well and through equipment used to separate the marketable oil from the water and other components of the fluid column. Paraffin, asphaltene and mineral scale deposits typically form in conduits used to transport this fluid mixture and restrict flow within the pipeline. These deposits and the associated congestion they create may further lead to the deterioration of pumps, valves, meters and other equipment utilized to propel and monitor the flow of the fluid through the pipeline system. Such deposits typically result in lost production and substantial expenditures for thermal, mechanical or chemical remediation to achieve and maintain full flow through a pipeline.
Many thermal exchange systems, such as cooling towers or boilers, utilize water as a heat transfer medium. Mineral scale and corrosion buildup within such systems can result in flow restrictions similar to those of oilfield pipelines. Deposits within the conduits of such systems typically restrict the flow of water through the system and adversely affect the operation of equipment such as pumps and valves.
Further, deposits within the walls of piping systems and on thermal exchange grids tend to act as a layer of insulation and inhibit the efficient transfer of heat carried by the water. Thus, contaminant deposits result in restricted flow, lost efficiency and increased energy consumption in these types of water treatment systems. Periodic descaling of heat exchange equipment typically results in process downtime and substantial labor and remediation expenditures.
In closed-loop systems where water is continuously circulated to facilitate heat transfer from one area of a system to another, chemical treatment of the water is commonly used to remove contaminant deposits and control algae, bacteria and other biological contaminants. Over time, the build-up of chemicals, minerals and other contaminants within a water column typically results in the continuously circulated water column being unfit for continued use. Chemical and contaminant laden water streams typically require additional treatment to render them suitable for discharge into a wastewater disposal system or for release into the environment. Chemical treatment is costly and increasingly gives rise to growing environmental concerns with the storage, handling and dispensing of dangerous chemicals.
These prior art methods of dealing with contaminants in fluid columns are costly, time consuming and in some instances pose harm to the environment. For these and other reasons the effectiveness of such methods ranges from marginal to unsatisfactory. One alternative to prior art methods has been magnetic treatment wherein the magnetic flux provided by a magnetic field generator is introduced to a contaminated fluid column. Magnetic treatment of fluid columns typically results in the reduction and elimination of scale and other deposits within conduits and on equipment utilized to propel a fluid through a system. Magnetic treatment may also be used to accelerate the separation of oil and water. Environmental regulations charge entities that generate contaminated fluid columns as part of a manufacturing process or an incidental spill or leak with the containment, treatment and elimination of pollutants from a fluid column prior to discharging the treated effluent into the environment. Numerous types of treatment systems are utilized in a variety of situations where discharge limits are of prime concern. Examples of contaminated fluid columns include water run-off from facility operations, industrial wastewater, oilfield production water and wastes associated with contaminated soil remediation.
Magnetic treatment may be utilized prior to passing a hydrocarbon-contaminated feedstock through an oil/water separation device to enhance the efficiency of the equipment in the removal of free-floating oil. However, while magnet treatment of a feed stream accelerates oil/water separation, contaminants such as suspended solids, typically remain within the fluid column. Thus, magnet treatment alone fails to address concerns faced by entities charged with the treatment of a fluid column prior to its discharge into the environment.
One method of contaminant separation may be accomplished by passing a contaminated feedstock between electrically energized electrodes to bond suspended and dissolved contaminants into larger particles to facilitate their extraction from the fluid column. For example, contaminant separation may be utilized to break oil/water emulsions, allowing the separated oil to be recovered from the water column. Contaminant separation may also be used to initiate the coalescing of many suspended and dissolved solids within a contaminated water column to accelerate the bonding of solid contaminants and enhance the water clarification process. While prior art contaminant separation devices may be of benefit in certain applications, they have a tendency to clog with solids carried within the feedstock. This typically interrupts the treatment process while the equipment is cleaned, creating delays in processing, substantial maintenance issues and other concerns. Further, prior art contaminant separation methods are typically limited in the range of feed stocks that may effectively be processed due to the equal and even spacing of the electrically energized electrodes within their reactors.
While the spacing of the electrodes in some prior art devices may be modified to achieve the desired results during the setup and initiation of treatment for a certain feedstock, changes in the composition of the feed stream typically result in undesired and substandard treatment of the modified feedstock. However, if the spacing of the electrodes within prior art devices is adjusted to treat a modified feed stream, undesired and substandard treatment typically results when the feedstock resumes its original composition.
There have been many attempts to improve prior art treatment methods. In many instances, the desirable treatment resulting from utilizing smaller laboratory reactors cannot be attained in field operations requiring larger flow rates. Many prior art devices utilizing reactor designs similar to that of the small laboratory reactors on a much larger scale in an attempt to achieve larger flow rates. However, merely increasing the size of the plates or lengthening an array of electrodes within a larger housing capable of larger flow rates fails to provide for similar treatment results attained with the smaller laboratory cells unless a proportional increase in the current and voltage supplied to the larger electrodes is provided. Therefore, an increase in the surface area of electrodes within a reactor without a proportional increase in amperage and voltage typically results in larger reactors failing to duplicate the treatment levels achieved by smaller reactors due to a proportional decrease in the number of electrons and metal ions per square inch dispersed into a fluid column relative to the increased flow rate of a feedstock through a reactor. However, providing increased amperage and voltage to larger cells of prior art devices typically results in deficiencies that include large power supply components requiring larger amounts of energy, electrical arching between electrode plates that leads to the pitting and uneven wear of electrode plates, an accelerated degradation of sacrificial electrodes and excessive heat generation.
Attempts by prior art devices to increase flow rates have typically resulted in a reduction in the types of contaminants that may be removed from a feedstock and a loss of efficiency when treating a broad range of fluid columns with the even spacing of electrodes typically found in such devices. Further, many prior art devices provide for the laminar flow of a feedstock through their electrodes. This typically reduces the exposure of a fluid column to the varying intensities of the electronic fields that may be found at varying distances from the electrode plates.
An additional deficiency of many prior art devices is the placement of their electrodes within a reactor housing so that substantial volumes of a feed stream pass between the outer electrode plates and the inner wall of a reactor, resulting in substantial amounts of the feedstock receiving little or no treatment. Further, prior art devices require a separate power supply for each array of electrodes formed from a particular electrically conductive material since differing levels of electrical voltage are typically required to control the reactions of the various metal electrodes with a fluid column. Multiple power supplies occupy additional space and require additional input power.
None of the attempts to improve prior art devices provide the benefits of the present invention. By departing from the prior art, the method and apparatus hereby disclosed provide a simple, effective means of retarding contaminant build up and removing existing deposits from the internal walls of conduits and the surfaces of equipment utilized in the transmission and storage of fluid columns. The method and apparatus disclosed herein provide for the variable spacing of electrodes, and arrays of electrodes comprised of dissimilar metals having distinct and variable surface area exposure, within a single readily accessible reactor housing that may be driven by a single power supply.
The instant invention may therefore be utilized in the treatment of a fluid column to facilitate extraction of contaminants from a feedstock for subsequent collection of the pollutants for disposal, reprocessing or recycling.